A radioactive element is an element which is subject to spontaneous degeneration of its nucleus followed by the emission of alpha, beta and gamma particles. All elements with atomic numbers greater than 83 are radioactive.
The given phrases that describe radioactive elements are-
They have a consistent number of particles
- the particles are alpha, beta and gamma particles.
They have a half-life that determines their rate of decay.
Explanation for other options:
Not all elements occur in nature. Radioactive decay rates may not be constant as the decay happens when a radioactive substance emits a particle. It is not possible to predict exactly when a given atom of a substance will emit a particular particle. When the radioactive element release energy and particles, it decays.
I believe that 2 is correct. :)
<span>Everyone has cells because these are the building
blocks of life. These tiny particles that clump into groups that form tissues,
organs, and organ systems are
what makes organisms distinct from non-living things that exist on Earth. Where
there are cells, life is present, and in its absence life cannot exist as we
know of today. Cells are responsible for bringing different species of
organisms that are found in different ecosystems all over Earth. They are tiny
but in groups they are responsible for every living organisms that have existed
through time. </span>
Answer:
American politician Elbridge Gerry, Vice President of the United States at the time of his death, who was Governor of Massachusetts.
Explanation:
The pectines on a male scorpion is longer because they also use it to find a female to mate with.
